The invention relates to a rotary assistance mechanism adapted to be coupled to a driven member capable of rotating alternately in both directions, in response to the rotation of a drive shaft . A mechanism of this kind includes a motor, means for reducing the speed of the motor and two clutches associated respectively with each rotational direction, and means for controlling the clutches so as to bring one of the clutches into operation depending on the direction and the amplitude of the torque exerted on the drive shaft whereby the driven member is driven by the motor and the reduction means in the desired direction, through the actuated clutch.
The invention relates more particularly to the rise of such rotary assistance mechanisms for motor vehicle steering.
The invention aims especially at making rotary assistance mechanisms of the kind in question more responsive and particularly reducing their resistant torque when the motor is stopped and when the driven member is driven by the drive shaft.